USMLE Clinical Medicine 3

Question 1

A 60-year-old man presents with lower back pain, hypercalcemia, anemia, and lytic bone lesions. Serum protein electrophoresis shows an M-spike. What is the diagnosis?

Accepted Answer

Multiple myeloma

Answer

Multiple myeloma presents with CRAB criteria: hyperCalcemia, Renal failure, Anemia, and Bone lytic lesions, with an M-protein spike on SPEP from clonal plasma cell proliferation.

Question 2

A patient with type 1 diabetes presents with nausea, vomiting, Kussmaul breathing, and fruity breath. ABG shows pH 7.20, glucose 450 mg/dL, and urine ketones positive. What is the treatment priority?

Accepted Answer

IV fluid resuscitation and insulin infusion

Answer

DKA treatment requires IV normal saline for volume resuscitation first, followed by insulin infusion (after K+ is ≥3.5 mEq/L) to suppress ketogenesis; potassium replacement is critical.

Question 3

A 70-year-old woman with osteoporosis has a compression fracture. DEXA scan shows T-score of -2.8. Which medication reduces fracture risk by inhibiting osteoclast function?

Accepted Answer

Alendronate (bisphosphonate)

Answer

Bisphosphonates like alendronate are first-line therapy for osteoporosis; they bind to hydroxyapatite and inhibit osteoclast-mediated bone resorption, reducing fracture risk by approximately 50%.

Question 4

A patient presents with fever, right lower quadrant pain, rebound tenderness, and elevated WBC. CT shows fat stranding around a dilated appendix. What is the diagnosis?

Accepted Answer

Acute appendicitis

Answer

Acute appendicitis presents with RLQ pain (McBurney point), fever, leukocytosis, and CT showing periappendiceal fat stranding with appendiceal dilation (>6mm), requiring urgent appendectomy.

Question 5

A 55-year-old man presents with severe epigastric pain radiating to the back, nausea, and vomiting. Serum lipase is 5x the upper limit of normal. What are the two most common causes?

Accepted Answer

Gallstones and alcohol

Answer

Gallstones (biliary pancreatitis) and alcohol abuse together account for approximately 80% of acute pancreatitis cases in the United States.

USMLE Practice Test

USMLE Practice Test

USMLE Clinical Medicine 3